The present invention relates in general to a display device, and, more particularly, the present invention relates to an organic electroluminescence display device (hereinafter referred to as “organic EL display device”) which is capable of producing a multi-colored display by combining organic EL elements, which are capable of emitting a white light, and color filters.
Recently, along with the advent of an advanced information-oriented society, the demand for personal computers, car navigation systems, personal digital assistants, information communication equipment and composite products of such equipment has been increasing. As a display device for use in these products, a display device which has a reduced thickness, is light-weight and exhibits a low power consumption is suitable. From this viewpoint, a liquid crystal display device which uses auxiliary illumination, a display device which uses self-luminous electro-optical elements, such as organic EL elements, and a plasma display device have been practically used.
In this type of display device, to realize a color display, unit pixels of a plurality of colors (usually, three colors consisting of red(R), green(G) and blue(B)) are arranged close to each other and, a color layer (a color filter or a color emitting layer) is formed for every pixel unit, thus realizing a so-called full color display.
In a process for manufacture of an organic EL display device that is capable of producing a full color display, the coatings in three-colors, which are produced by a mask vapor deposition method, are formed separately for forming an organic EL layer. When a large-sized board that is capable of producing a large number of substrates at a time is used for enhancing the throughput and for reducing the manufacturing cost, there exists a limit with respect to the manufacturing accuracy of a mask and the positioning accuracy that can be attained in the mask vapor deposition method. Further, since the mask is liable to easily suffer from a change in the size thereof due to the heat radiation from a vapor deposition source, it is difficult to achieve a high yield ratio. Still further, the operational efficiency of a manufacturing facility is lowered, since a step to treat foreign substances in the vapor deposition atmosphere and the exchange of masks require a considerable time.
To cope with such drawbacks, various techniques have been known. Japanese Patent. Laid-open 2004-47387 (Patent literatures 1) and Japanese Patent Laid-open 2004-55355 (Patent literatures 2) disclose an organic EL display device having a top emission structure in which a first substrate, having an organic EL element formed thereon, and a second substrate, having a color changing medium formed thereon by a photolithography method, are laminated to each other with a given gap therebetween.
Japanese Patent 3395841 (Patent literature 3) discloses a method of manufacture of liquid-crystal-panel filters in which wettability varying layers are formed on a smooth transparent substrate and respective color filter dyes are selectively applied to the wettability varying layers by making use of the difference in wettability.
Japanese Patent Laid-open Hei7(1995)-220871 (Patent literature 4) discloses an organic EL display device which produces a full color display by combining color filters with a white organic EL element.
Japanese Patent Laid-open Hei10(1998)-255983 (Patent literature 5) discloses a display element which enables the emission of light of three primary colors with high efficiency by combining light emitting members, pigment converting members and color filters.
Besides the above-referenced literatures, Japanese Patent Laid-open 2003-282250 (Patent literature 6), Japanese Patent Laid-open 2003-187959 (Patent literature 7), Japanese Patent Laid-open Hei11(1999)-106934 (Patent literature 8), Japanese Patent Laid-open Hei11(1999)-242916 (Patent literature 9), Japanese Patent Laid-open Hei7(1995)-199165 (Patent literature 10), Japanese Patent Laid-open 2000-3786 (Patent literature 11) and Japanese Patent Laid-open 2004-22541 (Patent literature 12) disclose related subject matter.